1. Field of the Invention
This invention relates to a multiple-line automatic packaging machine capable of automatically and continuously form-fill-sealing multiple stick-like packages at a time, and more particularly to a multiple filling device suited to be used for such a multiple-line automatic packaging machine.
2. Brief Description of the Prior Art
A typical conventional automatic packaging machine comprises the steps, as discussed for example in Japanese Utility Model Publication No. 54327/1983 and Japanese Patent Publication No. 272511/1997, for slitting a rolled-up packaging material consisting of a wide sheet film which is uniformly printed into a predetermined number of parts, sealing the packaging material (i.e., packaging film) vertically and then horizontally, filling material to be packaged (i.e., content material) into the packaging film and cutting the packaging film, all in a continuous manner. For filling content material, a conventional automatic packaging machine generally uses a multiple-line auger filling device such as the one illustrated in FIG. 3.
In FIG. 3, reference numeral 20 denotes a hopper made into laterally long shape to hold content material. 21R . . . denotes supply nozzles of small in diameter, each is fixed vertically at the bottom of the hopper 20 at an equal distance between them. 21 . . . denotes rotating shafts, each is fixed inside the hopper 20 and separated at an equal distance therebetween, with its lower end goes inside of the supply nozzles 21R . . . respectively. 21M . . . denotes driving motors for the rotating shafts 21 . . . each is mounted on the upper plate 22 located over the hopper 20. 21S . . . denotes feeding screws, each is fixed to the respective rotating shafts 21. 20X denotes a cover to the hopper 20. As illustrated, the hopper 20 holds content material P in its inside 20H. When rotating shafts 21 are driven by respective driving motors, feeding screws 21S . . . take content material P into supply nozzles 21R . . . and then, content material P is fed, through respective supply nozzles 21R . . . , into the packaging film which is formed and sealed into multiple tubes (not shown).
However, it is not suitable to use a conventional multiple-line automatic packaging machine as described above for packaging certain types of content material P, for example, powdery material like milk powder or fragile granules. The reason is that, when feeding screws 21S . . . rotate in one direction, content material P gradually moves to one side of the hopper 20 and becomes blocks there, causing problems like uneven flow of content material P into respective supply nozzles 21R . . . resulting in unacceptable packages made with content material less than the specified volume or weight, or granular content material P ground to powder resulting in unacceptable packages made with content material out of specifications.
Therefore, the technical theme of present invention is to offer a multiple filling device designed, when content material is fed to a multiple-line automatic packaging machine through multiple supply nozzles fixed in parallel, to agitate content material held in the hopper to prevent it from becoming blocks and to ensure its uniform supply into respective supply nozzles and that, without having it ground to powder.
The object of the present invention is to provide those two items of claim discussed below to the multiple filling device comprising a hopper made into laterally long shape, having multiple supply nozzles vertically fixed at its bottom at an equal distance between them, multiple rotating shafts with feeding screws inside the hopper, each goes into the respective supply nozzles, and driving motors. The multiple filling device is designed to have each rotating shaft rotate by respective driving motors, thus content materal held in the hopper is taken by the feeding screws into respective supply nozzles and is fed downward.
(1) To divide the inside of the hopper, at least at its bottom area, according to the number of rotating shafts, by means of walls on the borders of the divided portions as if making multiple rooms with their tops open, and provide an agitating blade in each divided portion to be rotated by a motor. (claim 1)
(2) To design a mechanism to enable multiple agitating blades, provided in respective divided portions, to be rotated by one driving motor in the reverse direction to that of the rotating shaft. (claim 2)
1. Owing to the features of claim 1 discussed in above (1), inner bottom area of the hopper holding content material is divided according to the number of rotating shafts into multiple divided portions with their tops open. An agitating blade rotates in each divided portion to agitate content material. Because of these features, therefore, content material does not move to one side of the hopper and become blocks there, but is fed uniformly into respective supply nozzles according to the rotations of feeding screws. Further, granular content material is not ground to powder, ensuring that it is packaged keeping its quality and shape.
2. Owing to the features of claim 2 discussed in above (2), all those multiple agitating blades provided in respective divided portions are rotated by one driving motor, enabling to simplify the structure of the multiple feeding device and to reduce its production cost. Further, since each agitating blade rotates in a reverse direction to that of the feeding screw, it surely prevents content material from moving to one side of the hopper, or from becoming blocks, or from being ground to powder. Because of these features, therefore, it ensures uniform feeding of content material into all of the supply nozzles and increase the accuracy of content material filled in each package.